Honorary Membership was limited to 10 from 1890-1900, and to 15 from 1901 onwards. Corresponding Membership was a lesser class of Honoris causa membership in the early years. A few honorary members, such as Barnard, were first made corresponding members for a short time before being recommissioned as honorary members.
Nation(s) |
Start | End | |
|---|---|---|---|
| Clemence, Dr. Gerald M. | USA | 1964 | 1974 |
| Frost, Prof. Edwin Brant | USA | 1906 | 1935 |
| Proctor, Miss Mary | USA | 1896 | 1957 |
| Rogers, Prof. William A. | USA | 1894 | 1898 |
| Pickering, Mr. William Henry | USA | 1894 | 1938 |
| Hubble, Dr. Edwin Powell | USA | 1951 | 1953 |
| Lowell, Prof. Percival Lawrence | USA | 1916 | 1916 |
| Robinson, Mr. Leif J. | USA | 2000 | 2011 |
| Stebbins, Dr. Joel | USA | 1958 | 1966 |
| Struvé, Dr. Otto | USA | 1959 | 1963 |